The cause of the explosion is not yet known. A state-run news agency reports that the initial blast caused several smaller explosions in the surrounding area.

The Xinhua news agency reported the explosion ripped through a warehouse carrying "dangerous goods" in the Binhai New Area. The explosion happened shortly after fire fighters were called to the scene, and the Chinese Public Security Ministry reports four fire fighters are injured and two have lost contact.

Tianjin is a city of about 15 million people in northeast China, about 100 miles outside Beijing.